Clarke actually proposed the type of orbit they used to reach the outer planets. The man not only got many things right, but came up with a lot of the concepts they would need to use within a decade or so. He was nothing, if not amazing. So much so that I'm going to assert that it's hardly fair to use him for an example on this topic. And there was a few more of them who matched this description as well. In my opinion, the difference lies in how much better science teachers were during the first half of the 20th Century. Today .............. not so much. Our schools need to get their collective acts together.